The present disclosure relates to a sheet processing apparatus and an image forming system including the same.
In general, a sheet processing apparatus connected to an image forming apparatus is known. The sheet processing apparatus is called a post-processing apparatus, for example. The sheet processing apparatus includes, for example, a punching device. The punching device performs a punching process on sheet members that are conveyed from the image forming apparatus.
The sheet processing apparatus may include a stapling device disposed following the punching device. In the stapling device, the sheet members being sequentially conveyed from the punching device are aligned on an inclined tray, and a stapling process is performed on the aligned sheet members.
In the sheet processing apparatus, it is necessary to temporarily stop conveying the sheet member each time the sheet member reaches a position at which it is subjected to punching. To enhance the sheet processing efficiency of the sheet processing apparatus, it is important that the stopping of conveying of the sheet member in the punching device has a minimum influence on a following sheet process.
Furthermore, in the sheet processing apparatus, to increase the compactness of the device and reduce the cost, it is desired that a motor for driving movable portions be shared as much as possible.
For example, when an entrance conveying roller and the following sheet discharge conveying roller in a device provided following the punching device are driven by the same motor, it is known to use an entrance conveying roller including a separation mechanism as the entrance conveying roller. The entrance conveying roller takes over conveying of the sheet member from a punching conveying roller. In this case, when a pair of rollers of the entrance conveying roller are separated from each other, the sheet discharge conveying roller can continue to operate without being affected by stopping of the punching conveying roller.